The present invention relates to folding multipurpose tools, and in particular to such a tool which may include a pair of pliers and several different tool bits and blades and that can be folded small enough to be carried comfortably in one""s pocket.
Folding knives and the like including blades or tool bits available to be unfolded from both ends of a handle have typically included springs in the back of the handle to hold each blade in its folded position or in its deployed position by pressing on the base of the blade. Not only does such a spring press against the base of a blade to hold it open or closed, but it also bears a considerable axially-directed load when a deployed blade or tool bit is used. For example, a knife acts as a lever tending to rotate about its pivot pin and a surface on the rear of the knife blade presses against an end of the spring.
Where a single spring is required to act upon tool members on both ends of a handle the spring has typically been held in place with respect to other parts of the handle by a rivet located centrally along the length of the handle.
The forces generated by use of a knife blade typically are fairly small, and small-diameter blade pivot pins and spring-holding fasteners are sufficient. Where pliers are supported by a pair of folding handles, however, the loads to be carried axially within a spring are potentially significantly greater. A rivet or other fastener holding or supporting a spring in a handle of such a tool would need to be larger, and a spring would need to have a correspondingly large area to receive such a fastener. For a tool including folding pliers and intended to be small enough to be carried in one""s pocket, that type of construction would result in an undesirably large tool.
Folding multipurpose tools of many types have been available in recent years, but most such tools including pliers large enough to be fairly strong are rather bulky, heavy, and industrial in appearance. Manufacture of more compact tools, using a single spring for multiple blades, has required careful adjustment during assembly in order to have pliers jaws and other blades and tool bits fold and extend crisply and without undesirable amounts of free play or friction. Use of an individual spring for each blade or bit has resulted in loss of compactness, making a tool requiring a pair of handles undesirably bulky. Smaller tools including folding pliers have been comparatively weak and thus of limited utility.
In some previously available multipurpose tools including folding pliers, various tool blades are available only after having to separate a pair of handles to reach those tool blades.
What is desired, then, is a multipurpose folding tool having a pleasant appearance, which has adequate strength, which can be folded or opened easily yet which feels secure, which can be manufactured satisfactorily without extremely close tolerances, and yet which is light enough and compact enough when in a folded configuration to be carried comfortably in one""pocket.
The present invention provides answers to the aforementioned needs for compactness, strength, and versatility in a multipurpose folding tool by providing such a tool in which a handle frame side member includes an integral laterally-extending flange, and in which a double-ended spring has a central portion Supported by and retained axially by the flange, while outer end portions of the spring are free to flex and are biased to bear upon the base portions of blades and tool members which are moveable about pivot axles between folded, or stowed, positions and extended, deployed positions.
The present invention thus provides a folding multipurpose tool including, in combination, a frame side member having a pair of opposite ends and an integral flange member located between the opposite ends and extending laterally from the frame side member, a pair of pivot axles, each extending through the frame side member at a respective one of its opposite ends, a first tool member having a base portion mounted on a first one of the pivot axles for pivoting movement between a deployed position and a folded position with respect to the frame side member, a spacer member located on the other one of the pair of pivot axles, and an elongate spring having a pair of opposite end portions and a central portion, the central portion being engaged with and supported by the flange, and a first one of the end portions of the spring resting on the base portion of the tool member and the other one of the opposite end portions of the spring resting on the spacer member.
In one preferred embodiment of the invention, the flange extending from the frame side member has an inner side and a pair of opposite end faces, and a central portion of the spring includes a back side supported by the inner side of the flange and a pair of abutment shoulders each located adjacent and facing toward a respective one of the end faces of the flange so that the end faces of the flange and the abutment shoulders of the spring cooperatively restrict longitudinal movement of the spring with respect to the flange.
In one preferred embodiment of the invention, two frame side members are interconnected by a flange and thus form a channel, and the elongate spring is located between the frame side members.
In another preferred embodiment of the present invention, such a channel faces openly in a first direction as part of a tool handle, and an additional frame side member with an integral laterally extending flange is also carried on the pivot axles, with the flange directed toward one of the frame side members interconnected by a flange. The additional frame side member is oriented to form a slot or channel facing in the opposite direction, and a spring is engaged with the flange on that additional frame side member. A base of a tool member is mounted on one of the pivot axles alongside the additional frame side member so that the tool members in the channel open in one direction with respect to the handle while the tool member located alongside the additional frame side member opens in an opposite direction with respect to the handle.
In one preferred embodiment of the invention, a separate tool member is located on each of the pivot axles alongside a frame side member, and base portions of the tool members engage each of the opposite ends of the spring.
In another preferred embodiment of the present invention, each of a pair of handles is connected pivotally to the base of a respective one of a pair of pivotally interconnected crossed tool members and at least one of the handles includes a frame side member with a laterally extending flange located between opposite ends of the frame side member, a pair of pivot axles, each extending through the frame side member at a respective one of the opposite ends, a base portion of one of the crossed tool members being mounted on one of the pivot axles for movement about that pivot axle between a deployed position and a folded position with respect to the frame side member, a spacer member being located on the other one of the pivot axles, and the handle also includes a beam spring having a pair of opposite end portions and a central portion, the central portion being engaged with the flange, a first one of the end portions of the spring being engaged with the base of the respective crossed tool member, and the other of the end portions being engaged with the spacer on the other one of the pivot axles.
In one embodiment of the invention, the crossed tool members are a pair of pliers jaws.
Another aspect of the present invention is the provision of a folding tool including an elongate spring with a pair of opposite ends each mounted on a respective one of a pair of pivot shafts associated with a frame side member, and wherein a surface of that spring presses elastically against a surface of a base of a tool bit attached to the frame side member by a pivot joint located generally between the pivot axles to retain the tool bit in a desired position with respect to the frame side member.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.